fix(server): name the player on every played word, and bound the process

PlayedWord.player_id was declared and read by the client but never set by
the server, so a room of three or four never showed who played each word.
The chain byline now comes from the room, with a producer-side test.

The process also gains the ceilings it was missing: a cap on live rooms and
on open sockets, a per-connection frame-rate limit so a payload-less frame
is no longer free, and an opt-in trusted-proxy list so the join limiter can
tell players apart behind the documented reverse proxy instead of putting
them in one bucket. The typed word is sanitized before the engine stores it,
since every seat is shown it; a room exiting on its idle clock releases the
sessions still bound to it; the dictionary builder escapes its SQLite path
like the store does and renames over the old database instead of deleting
it first.

README.md

@@ -189,9 +189,12 @@ Configuration is environment-only; every variable has a working default.
 | `NOITU_GRACE` | `30s` | How long a disconnected player's seat is held for a reconnect |
 | `NOITU_ALLOWED_ORIGINS` | *(unset)* | Comma-separated origin allowlist. Unset means same-origin only |
 | `NOITU_WEB_DIR` | *(unset)* | Built frontend to serve. Unset serves the API alone |
+| `NOITU_TRUSTED_PROXIES` | *(unset)* | Comma-separated proxy addresses or CIDRs whose `X-Forwarded-For` is believed. Unset keys limiters on the socket peer |
+| `NOITU_MAX_ROOMS` | `1000` | Ceiling on live rooms across the process; a creator past it is told `server_full` |
+| `NOITU_MAX_CONNECTIONS` | `2000` | Ceiling on open WebSockets; the next upgrade gets HTTP 503 |
 
-An invalid duration is logged and ignored rather than silently changing the
-rules of the game.
+An invalid duration or count is logged and ignored rather than silently
+changing the rules of the game.
 
 Endpoints: `GET /ws` (Protobuf over binary WebSocket frames), `GET /healthz`,
 and — when `NOITU_WEB_DIR` is set — the frontend on everything else, with